True Refrigerator Error Code dor: Door Open Alarm
Dor on a True commercial refrigerator with a Danfoss ERC control means the door has stayed open too long. Close the door fully and check that it latches. If the code keeps returning with the door shut, the door switch or gasket needs a look.
Low: an operator alert about the door; the refrigerator keeps running while the door is closed.
- Code
- Dor
- Maker
- True
- Equipment
- Reach-in refrigerators
- Applies to
- TRUE commercial refrigeration appliances with Carel, Danfoss (ERC, ETC), Dixell and LAE display controls
What does True error code Dor mean?
Dor is the door open alarm on the Danfoss ERC control used in True commercial refrigeration. The control watches a door input and runs a timer while that input says the door is open. If the time passes the alarm delay, it shows dor and the unit lets the operator know the cabinet is losing cold air. The manual's table gives the display text, Door open alarm, and the short meaning that the door has been open too long. It does not publish the delay time, list causes, or describe a reset step. In practice an open door is the plain answer, such as a delivery in progress or a door that did not latch. But the control only knows what its door input reports. A door that is physically closed can still read as open if the switch is out of position, and a worn gasket can keep a door from seating. The alarm exists to protect product temperature, since warm kitchen air entering the cabinet raises the load on the evaporator and can cause frost buildup.
Affected models and control systems
True lists dor in the Display Code Definitions for the Danfoss ERC control. The same manual section covers Carel, Dixell and LAE displays on other True refrigerators, each with its own code set, so confirm your unit's display type before relying on this meaning.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Dor on the Danfoss display
- The door looks shut but does not fully seat against the gasket
- Alarm tone or flashing display until the door is handled
Possible causes
Likely causes — what usually sits behind error code Dor on this control. A technician confirms which one it is before any part is replaced.
- Door has stayed open longer than the alarm delay
- Door not latching because of a bent hinge or a worn self-closing mechanism
- Door switch or magnet out of position so the control reads open when the door is closed
- Product or a tray sticking out and holding the door slightly ajar
Safe checks before calling for service
- Close the door firmly and watch whether it latches and stays flush all around.
- Remove any pan, box or product that touches the door edge and keeps it from closing.
- Look at the gasket for tears or sections that have popped out of the channel.
- Wait a minute and see whether dor clears once the door has stayed shut.
- Note whether the alarm appears only when the door is closed, and tell the technician.
How a technician diagnoses error code Dor
- Read the code and confirm the door is physically closed and latched.
- Check door alignment, hinge condition and gasket seal along the full edge.
- Test the door switch or reed input by opening and closing the door while watching the control input.
- Check the alarm delay setting against the unit's data sheet.
- Inspect the wiring to the door input for damage at the hinge side.
- Replace the switch or gasket only after the test points to it.
- Door switch wiring runs close to line-voltage circuits behind the cabinet trim that should not be handled live.
- Adjusting alarm delay parameters needs the control's access method and the unit's factory data.
- Hinge and closer repair may need the door removed, which can damage the gasket and cabinet if done without tools.
Technical reference
- Document
- Commercial Refrigeration General Control Guide
- Edition
- TEC_TM_001 | REV. C | EN, 09/3/2025, P#811072
- Models / control
- TRUE commercial refrigeration appliances with Carel, Danfoss (ERC, ETC), Dixell and LAE display controls
- Section
- Electronic Control (with Display) - Display Code Definitions: Carel p. 74, Danfoss ERC/ETC p. 87, Dixell p. 96, LAE p. 110
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related True reach-in refrigerator error codes
Is it safe to keep using the refrigerator with dor showing?
Yes, if the door is closed and the code clears. If it stays on with a closed door, food temperature should be watched because the control may be misreading the door.
Does dor go away by itself?
Yes, once the door input reads closed. If it does not, the input or the door seal is the likely problem.
Does dor mean the cabinet is too warm?
Not directly. It only reports the open door, though a door left open long enough will let the temperature rise.
Need help with True error code Dor?
A technician confirms the cause on site and gives you the price in writing before any work starts.